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jiri 2005-02-17 00:30:09 +00:00
parent d568cfc24b
commit ea56e7380d
1 changed files with 38 additions and 21 deletions
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59
diis.h
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@ -25,15 +25,15 @@ class DIIS
public:
DIIS(const int n, const bool core=1);
~DIIS();
Te extrapolate(T &vec); //vec is input/output; returns square residual norm
typename LA_traits<T>::normtype extrapolate(T &vec); //vec is input/output; returns square residual norm
};
template<typename T>
DIIS<T>::DIIS(const int n, const bool core) : dim(n), incore(core), bmat(n+1,n+1)
DIIS<T>::DIIS(const int n, const bool core) : dim(n), incore(core), bmat(n,n)
{
st=incore?NULL: new AuxStorage<Te>;
stor= incore? new T[dim] : NULL;
bmat= (Te)0; for(int i=1; i<=n; ++i) bmat(0,i) = (Te)-1;
bmat= (Te)0; for(int i=1; i<n; ++i) bmat(0,i) = (Te)-1;
aktdim=cyclicshift=0;
}
@ -47,13 +47,13 @@ if(stor) delete[] stor;
template<typename T>
typename DIIS<T>::Te DIIS<T>::extrapolate(T &vec)
typename LA_traits<T>::normtype DIIS<T>::extrapolate(T &vec)
{
//if dim exceeded, shift
if(aktdim==dim)
{
cyclicshift=(cyclicshift+1)%dim;
for(int i=1; i<dim; ++i)
for(int i=1; i<dim-1; ++i)
for(int j=1; j<=i; ++j)
bmat(i,j)=bmat(i+1,j+1);
}
@ -62,48 +62,65 @@ else
//store vector
if(incore) stor[(aktdim-1+cyclicshift)%dim]=vec;
else st.put(vec,(aktdim-1+cyclicshift)%dim);
else st->put(vec,(aktdim-1+cyclicshift)%dim);
//calculate overlaps
bmat(aktdim,aktdim)= vec.dot(vec);
if(incore)
for(int i=1; i<aktdim; ++i) bmat(i,aktdim)=vec.dot(stor[(i-1+cyclicshift)%dim]);
if(aktdim==1) return (typename LA_traits<T>::normtype)1000000000;
//calculate difference;
vec.copyonwrite();
if(incore) vec -= stor[(aktdim-2+cyclicshift)%dim];
else
{
T tmp=vec; //copy dimensions
for(int i=1; i<aktdim; ++i)
T tmp=vec;
st->get(tmp,(aktdim-2+cyclicshift)%dim);
vec -= tmp;
}
//calculate overlaps of differences (if storage is cheap, they could rather be stored than recomputed)
typename LA_traits<T>::normtype norm=vec.norm();
bmat(aktdim-1,aktdim-1)= norm*norm;
if(incore)
for(int i=1; i<aktdim-1; ++i)
bmat(i,aktdim-1)=vec.dot(stor[(i+cyclicshift)%dim] - stor[(i-1+cyclicshift)%dim]);
else
{
T tmp=vec;
T tmp2=vec; //copy dimensions
st->get(tmp2,(0+cyclicshift)%dim);
for(int i=1; i<aktdim-1; ++i)
{
st.get(tmp,(i-1+cyclicshift)%dim);
bmat(i,aktdim)=vec.dot(tmp);
st->get(tmp,(i+cyclicshift)%dim);
tmp2 -= tmp;
bmat(i,aktdim-1)= -vec.dot(tmp2);
tmp2=tmp;
}
}
//prepare rhs-solution vector
NRVec<Te> rhs(dim+1);
NRVec<Te> rhs(dim);
rhs= (Te)0; rhs[0]= (Te)-1;
//solve for coefficients
{
NRSMat<Te> amat=bmat;
linear_solve(amat,rhs,NULL,aktdim+1);
linear_solve(amat,rhs,NULL,aktdim);
}
//build the new linear combination
vec.copyonwrite();
vec *= rhs[aktdim];
vec = (Te)0;
if(incore)
for(int i=1; i<aktdim; ++i) vec.axpy(rhs[i],stor[(i-1+cyclicshift)%dim]);
for(int i=1; i<aktdim; ++i) vec.axpy(rhs[i],stor[(i+cyclicshift)%dim]);
else
{
T tmp=vec; //copy dimensions
for(int i=1; i<aktdim; ++i)
{
st.get(tmp,(i-1+cyclicshift)%dim);
st->get(tmp,(i+cyclicshift)%dim);
vec.axpy(rhs[i],tmp);
}
}
return rhs[0];
return norm;
}